diff --git a/clang-tools-extra/clangd/refactor/tweaks/PopulateSwitch.cpp b/clang-tools-extra/clangd/refactor/tweaks/PopulateSwitch.cpp
--- a/clang-tools-extra/clangd/refactor/tweaks/PopulateSwitch.cpp
+++ b/clang-tools-extra/clangd/refactor/tweaks/PopulateSwitch.cpp
@@ -166,7 +166,10 @@
 
   std::string Text;
   for (EnumConstantDecl *Enumerator : EnumD->enumerators()) {
-    if (ExistingEnumerators.contains(Enumerator->getInitVal()))
+    // Try to insert this Enumerator into the set. If this fails, the value was
+    // either already there to begin with or we have already added it using a
+    // different name.
+    if (!ExistingEnumerators.insert(Enumerator->getInitVal()).second)
       continue;
 
     Text += "case ";
diff --git a/clang-tools-extra/clangd/unittests/TweakTests.cpp b/clang-tools-extra/clangd/unittests/TweakTests.cpp
--- a/clang-tools-extra/clangd/unittests/TweakTests.cpp
+++ b/clang-tools-extra/clangd/unittests/TweakTests.cpp
@@ -2980,6 +2980,12 @@
             void function() { switch (ns::A) {case ns::A:break;} }
           )"",
       },
+      {
+          // Selection on duplicate token enum
+          Function,
+          R""(enum Enum {A,B,b=B}; ^switch (A) {})"",
+          R""(enum Enum {A,B,b=B}; switch (A) {case A:case B:break;})"",
+      },
   };
 
   for (const auto &Case : Cases) {